The invention relates to a centrifugal force speed governor for internal combustion engines with fuel injection, and in particular to idle and maximum speed governors having at least a negative adjustment capability.
Centrifugal force speed governors are known, see for example German Offenlugungsschrift (laid-open patent application) 2,308,260, wherein a lever-like control element pivoted to an adjusting member and forming part of a spring-and-lever controlled adapting device is capable of controlling a fuel supply rate changing in the opposite direction of regulation; that is, the fuel supply rate adjusting member is displaced in the direction of increasing fuel supply when the angular speed increases, in order to achieve a so-called negative adjustment. Because the lever-like control element in its role as a transmission member from the adjustment member to an intermediate lever is directly linked to both parts, its adaptation motion controlled by adaptation springs for a full-load adaptation is maintained even when the position of a linkage member, serving as a setting member, is altered; that is, for partial load. This is undesirable in many engines, with the reduced fuel supply rate controlled by negative adjustment at low angular speeds possibly causing unstable engine operation. The described adaptation is used in particular to so alter the maximum fuel rate supply adjusted for full-load operation over the largest possible range of angular speeds so as to correspond to the fuel supply required by the engine. It is used furthermore for smoke-free combustion, or for a particular application (loaded engine), or so as to be very close to such states.
Also, the fuel supply rate for modern fuel injection engines is increasingly affected by more stringent regulations regarding the exhaust gases. Again, the increase in fuel supply with increasing angular speed determined by the negative adjustment results in improved engine acceleration. Many engines also require a positive as well as a negative adjustment, that is, the adaptation system first controls an increasing or constant for increasing the fuel supply for a given range of angular speed when the angular speed increases, then the fuel supply drops as the angular speed increases further. Such adaptation behavior may also be implemented by means of the governor of the state-of-the-art, although with the drawbacks already stated.